1. Field of the Invention
This invention pertains to the sealing of water confining earth formations and, more specifically, to the use of local soil materials in the formation of a water barrier.
2. Description of the Prior Art
The prevention of water leakage through ground formations such as dams, dikes, wells, ponds, reservoirs, canals and the like with bentonite and other expanding lattice clays has long been known. The magnitude in size of such formations, however, and the concomittant large quantities of clay needed to seal the formations has made cost a prohibitive factor. This is particularly true when the appropriate clays and/or other sealing materials must be transported to the ground formation site.
In the case of solar brine concentration ponds, U.S. Pat. No. 3,774,402 discloses the use of readily available phosphate slimes to reduce the permeability of the pond bottom. This is an inexpensive improvement which obviates the disadvantage of clay linings which deteriorate upon exposure to salt solutions. However, the necessary steps of slime recovery, concentration and application are significant detriments to the large-scale use of such a technique.
Another patent that utilizes inexpensive materials available in large quantities is U.S. Pat. No. 3,732,697. This patent discusses the use of industrial liquid waste materials mixed with loose earth to form a lining for waste disposal evacuations. The purpose of the lining is to prevent contamination with adjacent underground water supplies. Obviously, such technique would not be available at remote locations or other areas that are not near waste disposal facilities.
Reconstituted shale found beneath a limestone quarry has been shown to have utility as an impermeable liner for sanitary land fills in U.S. Pat. No. 4,030,307. Unfortunately, such shale does not exist everywhere one wishes to construct an earth formation for the containment of water. Additionally, the shale must be mined by drilling, blasting and crushing followed by screening. Unquestionably, these operations on a commercial scale require massive expenditures for labor and equipment.